| Re: [riena-dev] Riena-Singletons |
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Hi Rienars, Aren´t OSGi services not some
other kind of singletons? I know they have a much nicer
name but like a singleton a service exists only once in a JVM and can be shared
from multiple clients. If such a service has session
dependent state we have to take care of it. Does RAP provide any patterns
for dealing with session dependent services? Tschüß, Stefan Von:
riena-dev-bounces@xxxxxxxxxxx [mailto:riena-dev-bounces@xxxxxxxxxxx] Im
Auftrag von Liebig, Stefan Hi Rienaers, While working thru our code base I have detected several
kinds of "singletons" (some of them I would not call them a singleton): 1.
the classical singelton - a single instance of class
(maybe created lazily or not) with the typical static getInstance() method
(sometimes it has a different name) with fields (state) 2.
the static singleton - this a class with only static
methods and static fields carrrying some state 3.
the pseudo classical singleton - a single instance of a
class with getInstance() but without fields (state) 4.
the utility singleton - a class with only static
methods without fields (state) 1. and 2. are "real" singletons (they have some
state). At these singletons we need to look a little bit closer when we also
want to use them within RAP. For them we can use SessionSingletonProvider and
SingletonProvider. How about 3. and 4., especially 3. ? Should we transform 3 to 4 (no more getInstance(), just
static methods)? Or … Should the getInstance() method always be named
getInstance()? Opinions, feedback, .. Tschüß, Stefan ------------------------------------------------------------- fon: +49 (0) 69 / 27 22 18 0
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